Population figures are difficult to compare, as no two sources extract data in the same way.

The census data for the civil parish of Gladsmuir includes Longniddry, Macmerry and the small village of Gladsmuir. The population increase shown by these figures can be largely attributed to an increase in the population of Longniddry; meanwhile, the populations of Gladsmuir and Macmerry declined gradually but steadily throughout the period.